Wax-thread sewing-machine



(No Model.) 3 Sheets-Sheet 1.

*0. F. HARLOW.

WAX THREAD SEWING MACHINE.

No. 328,929. Patented Mar. 6,

ATTORNEY.

N. PETERS, Phnlu-Lflhognpher. wuhin mn. D. c.

3 SheetsSheet 2/ W O L R A H R C WAX THREAD SEWING MACHINE.

Patented Mar. 6, 1888.

M llVVEfl/TOH,

BY g5 ATTORNEY,

WITNESSES M (No Model.) 3 Sheets-Sheet s. v

c. F. HARLOW. WAX THREAD SEWING MACHINE.

No. 378,929. Patented Mar. 6, 1888.

'IIIIIIIJI/IA GNU/M15)" PATENT OFFICE.

CHARLES F. HARLOW, OF BOSTON, MASSACHUSETTS.

WAX=TH READ SEWING=MACHINE.

SPECIFICATION forming part of Letters Patent No. 378,929, dated March 6, 1888.

Application filed February 17, 1887. Serial No. 227,970. (No model.)

To all whom it may concern:

Be it known that I, OHARLEs F. HARLOW, of Boston, county of Suffolk, and State ofMassachusetts, have invented a new and useful Improvement in Sewing-ll/Iachines, of which the following is a specification.

Myinvention relates to a sewing-machine of that class wherein a loop-stitch is made by means of a vibrating looper.

My invention, while well suited to a machine for ordinary sewing, is especially adapted to a machine for sewing with waxed thread. It involves two principal featuresnamely, the stitch-forming mechanism and the automatic tension device.

Wax-thread sewing-machines have heretofore constituted a special class by themselves, differing materially in construction and operation from the ordinary general type ofsewingmachine in which unwaxed thread is employed. For example, in waxed-thread sewing-machines which now make the loop-stitch an awl is usually present, which is driven downward through the work by the upper mechanism. When the awl rises, the needle, which is hooked or barbed, follows it through the material and receives a threadloop from a small horizontally-swinging arm which is supported from the upper portion of the machine. W'hen the needle descends, it carries a loop of thread through the loop last formed. The feeding of the work through the machine is effected by a lateral movement of the needle. This illustration is fairly typical of other machines of its/class. I propose to do away with this special class of machine by giving to the ordinary sewing-machine the capacity of working with waxed thread as-well as with unwaxed thread. In other words, I propose a machine ent in the various forms of sewing mechanism now in the market. \Vith this object in view, I recognize the present difficulties incident 'to wax-thread sewing, which difficulties have so far rendered necessary the barbed needles, the awls, and other special devices. I find that, among other disadvantages, the wax on the thread tends to bind the thread to the needle, clogging the eye, and even forming in masses around the needle, so that an ordinary rotary looping-hook is prevented from engaging with the loop. This especially happens when the thread receives its wax from the molten contents of a wax-box just before it passes to the needle, for then the wax, not having had much time to harden, is soft and adhesive. So, also, the wax offers great frictional resistance to moving parts over which the thread passes, and hence, when, as incertain forms of sewing-machines, a considerable quantity-say four or five inches-of thread is necessarily let off at each stitch, all of this thread encircling a rotary hook or looper is apt to bind against the same and stick, refuse to come off, and so become tangled. Again, if the loop be made in a plane but slightly inclined from the vertical, as bya rotary hook or looper, the needle carrying the new loop is apt to rub against the. thread of the loop, and again there is binding or adhesion. Furthermore, when so much thread as is usually necessary is let off it is a difficult matter to take up the slack when that thread is wax-coated. Five inches or soof waxed thread drawn at every stitch through a piece of heavy cloth or leather offers much resistance and far more than happenswhen ordinary smooth-finished nnwaxed thread is used.

In order to carry out my object, I follow this principle-namely, to reduce the movements of the stitch-forming devices to-a minimum and to simplify the same to the highest at tainable degree, to reduce the amount of thread necessary for the formation of each stitch correspondingly to a minimum, and to produce from this minimum amountof thread a loop through which the needle must positively pass at every descent without contact of the thread on the needle with the encircling thread of the loop.

The means and instrumentalities whereby I carry this principle int-o practical effect are fully, clearly, and exactly set forth in the following specification.

In the accompanying drawings, Figure 1 is a side elevation of my machine, a break being shown at about the middle portion thereof simply to reduce the width of the drawing. Fig. 2 is a transverse section of the automatic tension attachment on the line at a: of Fig. 1. Fig. 3 is a plan view of my machine from above, showing a portion of the frame broken away in order to exhibit a horizontal section of the automatic tension attachment and adjacent parts. Fig. 4 is a front elevation of the stitch-forming mechanism, feed bar and plate, stitch-regulating device, and adjacent parts. Fig. 5 is a side elevation of the same.

- Fig. 6 is an end elevation of the machine, giving the same view of thesame parts represented in Fig. 4, together with the needle and presser bars, frame, &c. Figs. 7 to 11, inclusive, illustrate the manner of forming the loopstitch. Figs. 7, S, and 10, inclusive, show the looper, spreader, and needle in elevatiomwith the cloth in section. Figs. 9 and 11 show the looper and spreader in plan View and the needie in section. These figures illustrate more particularly the action of the spreader in spreading or opening the loop.

Similar letters of reference indicate like parts.

1 is the standard of the machine.

2 is the main shaft, journaled in the arm 3 of said standard and provided with a driving or belt pulley, 4, by which it is rotated. The motion of the main shaft 2 is transmitted by bevel-gears 5 to a vertical shaft, 6, journaled in the upright portion of the standard, as shown in Fig. 1. Vertical shaft 6 communicates its motion by bevel-gears 7 to the camshaft S, which rotates in hearings in the lower portion, 9, of the standard.

I will first describe the mechanism which aetuatcs and controls the needle and presserroller.

At the extremity of main shaft 2 is a disk, 10. Eecentrically pivoted to the face of said disk is a pitman, 11, which is also pivoted to the needle-bar 12. Said needle-bar reciprocates vertically in guides 13 and 14.- at the end of the arm 3, and is actuated by said pitman, which in turn is operated by the rotation of shaft 2.

15 is the presser-bar, which also moves in the guides 13 and 14. At the lower end of said bar is pivoted a presser-roller, 20. Near the upper portion of said bar is a crossbar, 16, upon which bears a fork formed at the extremity of the leaf-spring 17. The other end of said spring is fastened by a screw, 18, to the upper side of the arm 3. Passing through said spring and entering a lug on the upper side of arm 3 is an adjusting-screw, 19. By means of the ad j USlJlIJg-SCIGW 19 the down ward pressure of the forked end of spring 17 upon the presser-bar 15 may be conveniently regulated.

Secured upon the presser-bar 15 is atappet, 21, which bears upon the end of a pivoted lever, 22, which has its fulcrum at 23. The prcsser-bar 15 is lifted against the action of the leaf-spring 17 by means of said lever 22. In order to hold said presser-bar 15 in an elevated position, the cam 24: is provided. Said cam has a suitable handle and is pivoted to the arm 3. In Fig. 1 the presser-bar is shown down. In order to raise it, the handle of the lever 22 is moved downward, and when the pressenbar is fully raised the cam 24 is turned so that its eccentric portion intervenes between the lever and cam-pivot, thus preventing said leverhandle from being lifted by the action of the spring which bears upon the presserbar.

Secured to the lower guide, 14-, is a vertical curved plate, 25. In said plate is a notch or recess, which, when the presser-bar 15 is down, receivesafixcd dog,26,which is rigidly secured upon said bar. By this means the presser-bar is prevented from rotating when the presserrollcr bears upon the work. 'When said presserbar is lifted, it maybe rotated in its guides 13 and 14, so that the dog 26 will rest upon the upper edge of the curved plate 25, and in this way the presser-bar may be held up without recourse to the cam 24, if desired.

In the periphery of disk 10 is formed a camgroove, 27, in which enters a pin on the end of one arm of the pivoted bell-crank take-up 28. The horizontal arm of said take-up carries a grooved roller, 29,over which the thread passes. By the rotation of disk 10 the takeup 28 is vibrated in proper time correspond ingly to the movement of the needle, so as to draw up the slack of the thread.

Secured to the lower end of the needle-bar 12 in any convenient manner is an ordinary eye-pointed needle, 30.

I will now refer more particularly to the feeding devices.

31 is the work-plate, which is at the summit of a hollow case, 32. Said case has the form of a pyramidal frustum which rises from the lower portion of the standard. The needle by the reciprocation of the needle bar 12 moves down and up through an opening in said work-plate in the usual way. The feed is of the well-known four-motion type and is arranged as follows: Upon the shaft 8 is a fixed eccentric, 33, which is received in a recess in the feed-bar 34, to which bar the eccentric in rotating gives the usual four motions. Secured to the feed-bar 34 is a bar, 35, which projects upward through the case 32 and terminates in the usual notched feed-plate, 36, which moves in an opening in the work-plate 31.

The stitch regulating mechanism is combincd with the bar 35 in the following manner: W'ithin the case 32 is secured a vertical slide, 37. Against said slide rests a sleeve, 38, through which the bar 35 passes. Said sleeve is pivoted on a block, 39, which receives the end of the screw 40. Said screw passes through a fixed nut, 41, inside the case .thus increasing the extent of feed of the work.

Conversely, when the sleeve. 38 is moved upward, the said radius is shortened and the feedplate moves over a less distance.

I do not lay claim herein, broadly, to the foregoing means and instrumentalities in a sewing-machine, except in so far as they enter into combination with the apparatus hereinafter set forth, which apparatus practically embodies my invention. Therefore I may modify or change the previouslydescribed mechanism. It should therefore be clearly understood that I do not limit my invention to use in connection with said previously-dc scribed mechanism, except so far as the same is hereinafter specifically claimed in combination therewith.

In a preceding port-ion of this specification I have set forth the principle of my invention, and in the following I describe the best means I now know of practically embodying the same. I have stated that the chief features of my invention are the stitch-forming devices and the automatic tension appliance. The stitch-forming devices are organized to produceastitch witha-minimumamountofthread, with minimum movement of mechanism, and in such away that the needle will positively and unfailingly pass through theloop without frictional contact of the thread in the needle above the eye with the thread of the loop. I mean by this that when the needle is passing down through the loop the thread in the needle does not rub against the loop-thread. The automatic tension device is organized so as to maintain a proper tension even under the small amount of draft of thread requisite, and

to this end to be controlled positively from the mechanism which actuates the stitch-forming devices.

I will first explain the stitch-forming devices and the manner in which the loop-stitch is made.

At the extremity of the shaft 8 is a disk, A, on the face of which is the cam-groove B, Fig. 4. O is the looper-bar, arranged within the case 32 and pivoted at D. At the extremity of the lower portion of said bar is a pin which enters the camgroove B. At the upper end of saidbar is the looper-hook E. Said hook is dctachably secured in a socket on said bar by the clamp-screw S. By the rotation of the shaft 8 the pin on the end of looper-bar O is caused to follow the cam-groove B, and in this way the said bar is caused to vibrate on its pivot D. The direction ofmovement of the looper is transverse the machine,

. and it willbe apparent from an examination position.

.effect is shown in Figs. 10 and 11.

of the form of the cam-groove B that the extent of motion of the looper is very small and is due to the change in shape in the groove B from the truly circular portion Qto the straight portion It. In a full-sized machine the distance moved over by the looper is about onehalf an inch. The point of the looper moves in a plane which approximates quite closely to the path of the needle, so that when said point moves forward it enters between thread and needle, as hereinafter explained. Beside the looper-bar is the spreader-rod F. This rod passes loosely through a guide, G, near the extremity of the looperbar, and a guiderecess, H, near the pivot of said bar. Its lowerportion is bent at right angles and is supported upon a pin, I, in said bar. Its lower extremity is again bent at right angles, and is received in a transverse slot in the end of alongitudinally-reciprocating bar, J. Said bar J is an arm from a lever, K, which is pivoted at its lower extremity, L, in a recess in the standard-flange M. On said lever is a pin,-N, which enters a cam-groove, O, on the periphery of the disk A. By the rotation of said disk the lever K is therefore vibrated on its pivot, the bar J is caused to reciprocate longitudinally, and in so reciprocating said bar rocks the spreader-rod F in its guides G H. At the upper extremity of the spreaderrod is the spreader P. The point of the spreader lies closely beside the point of the looper, as shown in Fig. 9, the spreader-point being curved toward the looper-point, so as to enable the two points to come into close juxta- The object of thus bringing these points together is that both may be thrust through theloop on the needle simultaneously and without danger of the thread entering be tween them. The spreader-rod F, being supported on the looper-bar, of course vibrates with the latter, but is turned on its axis, for the purpose now to be described, by means of the reciprocating bar J.

The operation of forminga stitch will easily be followed from Figs. 7 to 11, inclusive.

Beginning with Fig. 7, here the needle is shown down and thelooper and spreader are retracted and ready to enter between the needle and the thread. The loop made by the previous stitch is on the needle. Thelooper and spreader as one move forward, both points simultaneously pass between the needle and the thread above the eye, the needle rises abovethe clothplate, and the condition of affairs appears as in Fig. 8. The old loop has run off the needle and the new loop is over the points of looper and spreader. The position of the loop over these points is clearly shown in the plan view,

Fig. 9. Now, while the looper and spreader are still forward, the needle begins to descend. At the same time the bar J moves so as to rotate the spreader on its axis, thus separating the spreader-pointfrom the looper-poin t. The The spreader spreads or opens the loop in a plane at right angles to the path of the needle, and

when the loop is opened the needle comes down between the looper and the spreader, as plainly shown by the section of the needle in Fig. 11. These two results are of especial importance. By opening the loop through the positive action of the spreader in a plane at right angles to the path of the needle linsure a wide opening or loop through which the needle must always go without possibility of failure. By causing the needle to carry its thread between the spreader and the looper I not only keep the descending thread away from the thread forming the encompassing loop, but I render the smooth polished surfaces of the looper and spreader actual guards between the parts of the thread to prevent any possibility of such contact.

. After the needle has descended, the looper and spreader are retracted and close, the loop slides off their points upon the needle, and the conditions represented in Fig. 7 again occur, thus completing the cycle of operations of making the stitch.

Of course the changes of movement of the looper and spreader and their necessary dwell, 8.20., are caused by the shape of the cam-groove B. This, as well as the proper timing of the motion of the bar J, controlling the spreader, and of the needle and feed-plate, will readily be understood by any mechanic, so that no special description thereof is here needed. I desire, however, to direct special attention to thefact of the very small range of movement ofthe looper. The looperhook vibrates simply to and fro. \Vith the spreader it takes the loop, opens it, and lets it go. All the mechanism in motion in the vicinity of the thread is the looper, which may move, say, half an inch, and the spreader, say, one quarter of an inch. No more thread need be let off than will allow for these motionssay three-quarters of an inch at each stitchand by reason of the very shortness of movement and the simplicity ofthe mechanism the speed of the latter may be augmented to a high rate. Thus it will be seen that not only is the mechanism which I have described especially adapted to meet the difficulties ofa wax-thread sewing-machine, but it is perfectly suitable for an ordinary machine such as now employed for household use. The moving parts are exceedingly light, their motion is positive, and they can be driven at high speed.

I will now describe in detail my automatic tension device, which is shown in vertical and horizontal section, respectively, in Figs. 2 and 3.

a is a tube having a flangeat one end, by which it is secured to the side of the arm 3 by means of screws Z). An opening in said arm corresponds to and prolongs the opening in the tube. Ir. said tube is a rod, 0, having an enlarged circular head, d, which covers the outer end of the tube a. Upon said rod, and between the head d and end of tube a, is a loose annular disk, 0. Said disk is prevented from turning on the rod 0 by a pin,f, upon said disk, which is received in a recess in the end of tube a. Said rod is diminished in diameter near the head d, and surrounding said (liminished portion of rod 0 is a coiled spring, 9. Said spring at one end bears upon the annular disk 0 and at the other end upon the shoulder on rod 0. At It is a bar of spring metal, in which bar is an opening through which rod 0 passes. Upon the end of rod 0, which may be threaded, is a head or nut, 1'. By suitably turning said nut the tension of spring-bar It may be regulated. The ends of the bar h bear against the inner side of the arm 3.

On the main shaft 2 is a cam,j, which at every rotation of said shaft meets the inner end of rod 0 and moves said rod outwardly against the resistance of the spring-bar h. The disk 6 is meantime maintained in contact with the head (Z by the action of the spring 1. It will be seen, therefore, that while the cam j is not acting upon the end of rod 0 the strong spring-bar h is holding the head (1, disk 0, and end of tube a in close contact; but when the cam j is acting then the tension of spring-bar his removed, the disk 0 becomes slightly separated from the end of the tube a, and the pressure of the disk against the head is that due to the comparatively weak spring 9.

The thread is led between the disk 0 and head d. \Vhile the cam j is not acting, the drawing through of the thread encounters the resistance due to the pressure exerted between head (Z and disk 0 by the action of spring-bar 71. 'While the cam j is acting, the resistance offered to the thread is simply that due to the pressure of disk 0 on the head d, caused by the expansion of the weak spiral spring g, which spring thus maintains the disk and head in constant contact.

It will be noticed that the cam j, being upon the shaft 2, is in direct mechanical communication with the stitch-forming mechanism and the take-up, so that the intermittent slackening of the tension device by its action is readily timed and rendered correspondent to the dralt of thread.

On the arm 3 is a lug, 42, to which may be attached a wax-box. (Indicated by dotted lines in Fig. 3.) The wax in this box may be kept in a molten state by any suitable heating contrivance and the thread maybe conducted through said wax in any known way.

I claim 1. In a sewing-machine, the combination, with a reciprocating eye-pointed needle, a work-support, and a vibrating looper for engaging the thread to form a loop beneath the said support, of a loop-spreader and means to cause said spreader to vibrate coincidently with theloopcr, the pointof the spreader having a seat at the side of the looper, and means for rocking the spreader away from and toward the looper in a plane at right angles to the path of the needle, substantially as set forth.

2. In asewing-mac'nine, in combination with a vertically-reciprocating eye-pointed needle Ins and a work-support, a vibrating looper-bar, a looper-hook on the end of said bar, a vibrating spreader-bar, a spreader-hook at the extremity of said spreader-bar and disposed beside said looper-hook, the points of said hooks being substantially coincident, and mechanism for rotating said spreader-bar on its own axis to cause said spreader-hook point to diverge from said looper-hook point, and thereby to open the loop received upon said hooks in a horizontal plane, substantially as described.

3. In a sewing-machine, in combination with a vertically-reciprocating eyepointed needle and a work-support, a pivoted looper-bar, O, looper-hook E, spreader-bar F, supported upon said looper-bar O, spreader-hook P, mechanism for vibrating said looper-bar on its pivot,

and mechanism for vibrating said spreader-bar on its own axis, substantially as described.

4. In asewing-machine, in combination with a vertically-reciprocating eye-pointed needle and a work-support, the rotary shaft 8, disk A, having face cam-groove B, looper-bar G, looper-hook E, spreader-bar F, supported on said looper-bar O, spreader-hook P, and mechanism for vibrating said spreader-bar on its own axis, substantially as described.

5. In asewing-machine, in combinationwith a vertically-reciprocating eye-pointed needle and a work-support, the rotary shaft- 8, disk A, having peripherical groove 0, pivoted vibrating 1ooper-barO,looper-hook E, spreaderhook P, pivoted lever K, having pin N, entering said groove 0, and slotted bar J, substantially as described.

ing pin N, entering said groove 0, and slotted bar J, substantially as described.

7. The combination, with stitch-forming mechanism and the vibrating looperbar 0, provided with guides, as G and H, and with a locking-pin, as I, of a spreadenbar extending loosely through openings in the guides G and H and into engagement with the pin, whereby the said spreader-bar is allowed a rocking motion and is looked in vertical adjustment, substantially as set forth.

8. The combination, with the vibrating looper-hook E,curved in one plane only,of the spreader-hook P and means to vibrate the same coincidently with the looper-hook, said spreader-hook having a bend in a plane substantially parallel with that in which looperhook is bent, and also a lateral bend a short distance back from its point, whereby the two hooks may be readily inserted between the thread and needle, substantially as set forth.

oHAnLEs F. HARLOW.

Witnesses:

AMBROSE EASTMAN, JAMES R. PowERs. 

